1. Technical Field of the Invention
This invention relates to a suture needle and its manufacturing processes. More particularly, the suture needle is used for medical treatment, in which a suture is previously inserted and fixed within a needle body.
2. Description of the Prior Art
Conventionally, there are known two types of suture needles. According to a first type of suture needle, every time a needle is used, a suture is hooked in an aperture of a needle body. According to a second type, the suture is previously fixed in a hole formed at a front part of the needle body at the manufacturing stage. In the first type, every time the suture needle is used, sterilization is required and the suture may be disengaged from the aperture of the needle body, so that it is an old-fashioned type. Today, the second type is prevailing in advanced countries. That is, it is also a disposable type.
[I] FIGS. 8(a) to 8(d) show repective views of a first embodiment of a conventional suture needle which is frequently used today. Numeral 1 is semicircular needle body made of stainless steel, which comprises a fixing part 2 for fixing a suture 3 at an end of the needle body 1. As shown in 8(d), the fixing part 2 consists of a hole 2a formed in an axial direction of the needle body 1. The suture 3 is inserted into the hole 2a and firmly fixed therein by caulking means.
According to a conventional process for manufacturing needles, a stainless steel thin rod is cut off with a suitable length for a needle body. Then, the hole 2a is bored by laser processing, drilling or the like. Subsequently, the suture 3 is inserted into the hole 2a manually and fixed therein by caulking means.
The aforesaid prior art has the following disadvantages and inconveniences.
(1) The depth of the hole 2a for inserting the suture 3 therein is limited in view of boring operation, so that fixation of the suture in the hole 2a is not always complete. Accordingly, disengagement of the suture from the hole may occur easily. If caulking stress is too strong, the needle body 1 may be broken or deformed.
(2) Since the needle body is provided, at one end, with the hole for inserting the suture, the needle body is inclined to be broken in the proximity of the hole.
(3) Since the needle body except for the hole portion is of a solid construction, its resilience is relatively low. Accordingly, there grows the danger that a pointed end of the needle body may be broken and retain in a body during sewing operation. Such accident may cause a serious condition.
(4) After the hole has been bored and the suture has been fixed therein, it is no more possible to clean the interior of the hole. Accordingly, it is impossible to wipe away any foreign matter that may remain in the hole during boring operation.
(5) After the suture has been inserted in the hole, sterilization must be carried out, but an inserted part of the suture is inconvenient for a complete sterilization.
(6) The boring operation including laser processing, drilling or the like requires high accuracy, so that it is a cumbersome work. It is very difficult to obtain a bore of a very accurate diameter effective to insert the suture thereinto.
(7) It is also a very cumbersome work even for skilled workers to insert and fix a soft and thin suture into such a minute hole. The daily output of such conventional suture needles is so limited that the production cost is expensive and quality is not always uniform.
[II] A second embodiment of the prior art will be described with reference to FIG. 9(a) to FIG. 10(b), in which every time a suture is used, it must be engaged with an end of the suture needle.
Symbol B1 is a typical conventional suture needle body formed by a stainless steel rod, in which B2 is a hole means for inserting a suture therein and B3 is a pointed end of the suture needle body B1.
FIGS. 9(b), 9(c) and 9(d) show respective section of the suture needle body B1, in which FIG. 9(b) is an elliptical section, FIG. 9(c) is a circular section and FIG. 9 (d) is a triangular section.
As shown in FIG. 10(b), the hole means B2 comprises a hole B2a for engaging with a suture, a pair of lugs B2b and a recess B2c thereupon. The pair of lugs B2b are contacted with each other at their upper ends and formed integrally at their lower end. Such structure is suitable for inserting the suture therein.
A process for manufacturing the aforesaid conventional suture needle comprises the following steps.
(A) Step of cutting off a stainless steel wire so as to conform to the diameter and length of a desired suture needle.
(B) Step of forming one unit obtained by the above step into a elliptical section by a flattening means.
(C) Step for forming about one third (needle front part) of such a member into a triangular section, a middle portion thereof into a circular section and a rear part thereof into an elliptical section.
(D) Step of forming a hole means for inserting into, and engaging with a suture, in the rear part of such member.
(E) Step of bending the whole of such member in a semicircular form.
The aforesaid conventional technique has the following disadvantages.
(1) The suture needle obtained by the aforesaid process is a solid body and its diameter is forced to be thick to increase strength.
Such a thick needle causes a patient strong pains.
(2) When such suture needle units are produced continuously, they must be lined up correctly and then necessary mechanical processings must be provided. Accordingly, the production cost is high.
(3) If a manual operation will be adopted to avoid the inconvenience of such a line-up process, the product cost will become much higher and the quality of finished products becomes unreliable.